150mm Schneider Krueznach Componon-S

Can anyone tell me what is this feature of my Componon-S that looks like it can be moved from one side to the other. I have never messed with it but I don't know what its purpose is and I have long lost any documentation for this lens. I check the Schneider site but I found nothing about this lens. Thanks.

Most likely it relates to the aperture settings. It may disable the aperture "clicks".
It may also allow you to set a "stop" for the aperture setting, which in turn permits you to rotate the aperture from fully open to a pre-set stop - e.g. f/11. This enables you to easily and repeatably move it from wide open (the setting) which ensures things are bright and optimized for checking focus or the image on the easel) to the aperture used for printing, all by touch and without having to read the aperture scale.

Thank you Matt.

Handy when using a Null Meter in color printing.

I will also say this.......I made the sharpest negative over the weekend, I mean I nailed the focus, even while using some front tilt as I'm getting better at focus on far and tilt on near. However, I am unsatisfied with the sharpness of that negative projected to 8x10 in the enlarger (LPL 4550XLG VCCE). So I'm investigating that, not sure if there's an alignment issue or what. The lens is clean as a whistle. My LPL is supposed to be factory aligned and not need alignment but I understand that may not always be the case. Now I have to figure out if I can align it, if I deed, it needs it.

If there is an alignment issue, the result will be sharp at some points, and not sharp at others.
How does the lack of sharpness manifest itself?

MattKing said:

If there is an alignment issue, the result will be sharp at some points, and not sharp at others.
How does the lack of sharpness manifest itself?

Click to expand...

At work now but will take a closer look at that this evening.....

Do you have a Peak-1 magnifier that can 'see' the corners? Also, if not using a glass carrier, the negative can move and blur when it heats up, making it seem as if it were out of focus.

BTW I use that same Schneider Componon-S 150mm for all my 4x5 too.

ic-racer said:

Do you have a Peak-1 magnifier that can 'see' the corners? Also, if not using a glass carrier, the negative can move and blur when it heats up, making it seem as if it were out of focus.

BTW I use that same Schneider Componon-S 150mm for all my 4x5 too.

Click to expand...

No I don't have the Peak that let's me see the corners. However I did see where I could adjust the lens stage on my LPL and it was not square with the baseboard. I believe I have the lens definitely more in line with the baseboard now, at least a level front to back and left to right on both the baseboard and the lens stage match nicely now. The print I made tonight looks sharper.....I believe the negative stage is good too.

You can check alignment with two pieces of mirror, each about 3x8". Towards the end of one scrape a small hole in the mirror backing so you can look through the mirror. Draw a horizontal/vertical cross through the scraped hole on the mirror side with a magic marger. Place the holed glass in the negative carrier, mirror side down. Put the other mirror on the baseboard, mirror side up. Peer through the hole at the other mirror. If aligned you will see a reflection of the hole and the cross. If not aligned then there will be an infinity of crosses fading away. Adjust the enlarger, if needed, to bring the cross patterns to align. Repeat the procedure lens stage to baseboard.

This method is good for checking but rather a PITA if the lens stage needs alignment.

It is the same effect as being in a mirrored elevator or mirrored room.

An easier method is to use a 'Zig-Align' laser alignment tool; no longer made but available on ebay et al..

I've also discovered that the focusing knob creeps slightly downward when I release it, I hope there is a way I can tighten it up without causing me pain.